The Big 10, like the Nerdy 9, before adding Nebraska, was 100% AAU institutions (note that prior to gaining Missou & Tx A&M, only UF and Vandy were AAU in the Academically Wimpy SEC). However, Nebraska was formerly an AAU institution although it was ousted in 2011 (Ouster Opens a Painful Debate Within the AAU). So, the idea that Nebraska's admission standards somehow went up when it joined is likely untrue. That article is very informative, and shows an exceedingly unfortunate TRUTH regarding Elite Academic Rankings in that it has little to do with quality and a VAST amount to do with Raw Magnitude. One interesting fact is that USF has greater Citation and Research production per faculty than many AAU institutions, but USF has the difficulties of (1) being from the South [A massive bias remains among the Northerners], (2) it's public, and (3) it's not a Flagship. Tx A&M is the Flagship of the Texas A&M University System (of which there are several). Texas, in fact, now has 6 different University Systems: Texas, Houston, North Texas, State, Tech & A&M systems (List of colleges and universities in Texas - Wikipedia). Only the A&M and University Systems have enough power to have Flagship members of the AAU, however.

This article tells of how vital Institutional Ranking is with regards to Conference Affiliation (formerly, the Big 10 limited itself strictly to AAU Institutions, although now, being a Carnegie Research I institution [a classification that expanded Vastly in their 2010 reclassification, can substitute] Academics matters in conference realignment

A note regarding Florida SUS institutions and the Carnegie Classification, which is basically a ranking by raw magnitude of Federal Research $$$ per year. The number of Research 1 institutions jumped from about 50 to over 100 in the 2010 reclassification. USF moved to the top in 2005, and even UWF was highly ranked in 2010, but they declined a higher classificaiton because they wanted to remain a regional institution. UCF, which was built largely by Military Grants, always wanted to be high, but simply lacked the faculty talent to take Research Money from the historical institutions; FSU shares a similar fate, while USF has been the #2 institution in Florida since shortly after 2000. UF is far and away the leader, but USF has had quite a lead on the other SUS schools since about 2000, partly due to a close friend of mine who bring multidisciplinary Federal $$ to Anthropology like it was Medicine.

The thing about Federal Funds is that the overhead is huge. While Florida State Grants bring 3-5% overhead, Federal Grants, depending on the University (Illinois Chicago was the leader last time I looked due to historical links with the US Navy [WW II stuff] at around 55-58%). Most major research institutions gain at least 30-40% overhead, which the University can expend at will. Most Doctoral Candidates and many Master's students are funded by Federal Research Grants, as are many by State, Corporate, and even Local Funding sources. USF, by the way, is one of the National Leaders for Corporate Grants, which is exceedingly strange given that Tempa is completely atypical of cities where high Corporately Funded Institutions locate. San Francisco, Boston, New York, Los Angeles and Chicago are more typical than primitive places like Tampa.